1. Field of the Invention
This invention relates to a method and assembly for treating living and non-living biological environments with varying doses of fluids in vitro, and more particularly to a vessel and closure assembly having means for delivering fluids to cell lines and tissue cultures.
2. Description of Related Art
The use of in vitro cell lines and tissue cultures in carrying out pharmacokinetic and toxicokinetic studies related to safety evaluations of new drugs is a growing area of scientific development. By using cell lines and tissue cultures, the need for large animal studies is reduced.
Pharmacokinetic and toxicokinetic studies depend upon the control rate of drug delivery and dose of drug to a cell line for multiple drugs simultaneously. Repeated drug administration can influence the toxicity of the drug by changing its metabolism and stimulating the cell's synthesis of certain proteins that can effect the drug's activity on the cell line.
Current technologies for studying in vitro pharmacokinetics and toxicokinetics use either a closed monolayer culture system (MCS) or a dynamic perfused cell system (DPCS). The MCS employs an immediate total dose application of the test drug. Its limitation is that it operates in essentially a single dose range which can be toxic due to over dose.
On the other hand, the DPCS acts as an in vivo circulating model. The in vitro route of bolus administration does not mimic the in vivo method of drug administration since their are no tissue masses to act as the sustain release matrix.
A need exists for a delivery system in order to carry out in vitro pharmacokinetic metabolic pathway studies of drugs, proteins, growth factors and other such biologicals. The need arises because it is experimentally undesirable to deliver fluids, such as drugs to cell lines and tissue cultures in bolus concentrations. Bolus concentrations cause the pharmacological dose to quickly and uncontrollably extend into the toxicological range.
Therefore, a special need exists for a drug delivery system which permits the control of drug delivery and provides an assessment of drug concentration on cell lines and tissue culture environments so as to establish a correlation of drug action with adverse reactions.
Such a need for a new type of drug delivery system for treating biological environments has not been suggested or taught in the literature.